Santa Rosa registered its hottest day of the year Friday as a heat wave gripping the West settled in, the beginning of a warm-up that is expected to keep the mercury soaring the next few days.
The full-on summer blast prompted officials to issue an excessive-heat warning in the San Francisco Bay Area, where temperatures were expected to top out over 100 in some areas, persisting through Tuesday evening.
In the North Bay, the hot spots Friday were Cloverdale and Calistoga, which tied at 104 degrees. Santa Rosa's 98 degrees Friday did not reach the 103-degree record for the date, set in 1976.
Santa Rosa's high temperatures are expected to hover near 100 degrees over the next few days.
The National Weather Service warned of a heightened risk of heat exhaustion and heat stroke. And the Sonoma County Department of Health Services said infants and children up to 4 years of age are especially vulnerable, along with seniors over 65.
A Spare the Air Alert also was issued for today by air pollution regulators, indicating unhealthy air quality and a request for people to drive less.
The scorching temperatures across the state and parts of the West were blamed on a high-pressure system brought on by a shift in the jet stream, which has been more erratic in the past few years.
The hot spot in California on Friday was Death Valley at 125 degrees. It was predicted to hit 128 degrees there today, but still shy of the all-time world record of 134 degrees reached a century ago.
The heat wave comes at the close of the second driest six-month period on record, and just ahead of the Fourth of July fireworks celebrations, elevating concerns about drought and fire danger.
From January to June, 6.71 inches of rain fell in Santa Rosa, second only to the 6.57 inches that fell in the same period in 1976.